The field of the invention is systems and methods for radiation treatment planning. More particularly, the invention relates to systems and methods for automated radiation treatment planning using physical objectives that are based on the physical properties of a radiation therapy system.
In radiation treatment planning it is desirable to compute optimal treatment plans that deliver an optimized dose to the patient. In these plans, varying levels of radiation are delivered using beam apertures from various angles around the tumor to deliver the highest dose to the tumor while minimizing dose to non-tumor tissues. Typically, treatment planning is done on a case-by-case basis by medical physicists, medical dosimetrists, or both. Treatment plans are based on a dose prescribed by a physician and are computed using radiation treatment planning software.
The process of treatment planning is iterative, in that the medical physicist or medical dosimetrist starts with a “guess” and enters a number of parameters into the system that he believes will be close to providing the prescribed dose to the target tissue while sparing other tissue from radiation. There are quite a number of parameters that can be modified, so the iterative process can many times be quite time consuming.
Given the importance of plan quality in terms of a given patient's probability of disease control and severe toxicities, there remains a need to provide a standardized methodology for how to consistently achieve a high quality radiation treatment plan. Currently, in clinical practice, a trial and error process is used to define the inverse planning objectives that yield a clinically acceptable plan. Though the treatment planning goals are simple (e.g., achieving conformal target coverage and a low dose to critical structures), achieving all of these goals simultaneously is difficult. Because of the technical challenge in developing a good treatment plan in a clinical setting, neither the physician, dosimetrist, nor medical physicist may be aware of what the best achievable plan quality is for a given patient. Accordingly, the quality of a treatment plan used clinically is both a reflection of the technology used and the quality of the inverse planning objectives chosen during plan optimization.
It would therefore be desirable to provide a method for radiation treatment planning that is capable of achieving a consistently high plan quality across different patients and therapy systems.